3D打印轻质高强钨材的力学性能研究

3D printing lightweight lattice structure to improve the mechanical properties of tungsten

摘要:

采用选择性激光熔化（SLM）3D打印方式成功设计和制造了具有点阵结构的钨材，结合有限元分析、扫描电镜、准静态单轴压缩试验探究了不同点阵结构下钨材力学性能的变化规律，分析了微观组织对力学性能的影响。结果表明圆弧型点阵结构可有效降低节点处的应力集中，保持点阵结构轻质、低孔隙率特性同时还维持着钨材的高强度力学性能，平均抗压强度达到535MPa，平均质量仅为1.25g，激光打印后圆弧点阵较立方点阵平均抗压强度提升93%，其中体心圆弧点阵（BCA）显示出更优抗压性能，极限抗压强度达到721MPa，结构致密度为理论值12.8%；力学性能指标接近于变形态。与立方点阵相比，圆弧点阵具有良好的能力吸收特性，后者相较前者总能量吸收值提升223%，圆弧点阵平均能量吸收达到1664J/cm3。此外，SEM图像显示圆弧点阵因其弧形特性，减少了打印中斜支柱的悬挂距离，成型效果优于立方点阵。

Abstract:

The selective laser melting (SLM) 3D printing method was applied to design and manufacture tungsten materials with lattice structures. The changes in the mechanical properties of tungsten materials under different lattice structures were investigated through finite element analysis, scanning electron microscopy, and quasi-static uniaxial compression tests. The influence of microstructure on mechanical properties was analyzed.The results indicate that the ARC lattice structure can effectively reduce stress concentration at the nodes, while maintaining the lightweight and low porosity characteristics of the lattice structure, as well as the high-strength mechanical properties of tungsten materials. The average compressive strength reaches 535MPa, while the average mass is only 1.25g. After laser printing, the ARC lattice has an average compressive strength increase of 93% compared to the cubic lattice, with the Body-Centered arc lattice (BCA) showing superior compressive performance, reaching a maximum compressive strength of 721MPa, and a theoretical structural density of 12.8%. The mechanical performance of 3D printed W is close to plastic processed sample. Compared with the cubic lattice, the arc lattice has good ability absorption characteristics, and the total energy absorption value of the latter is increased by 223% compared with the former, and the average energy absorption of the arc lattice reaches 1664J/cm3. In addition, the SEM image shows that the arc lattice reduces the hanging distance of the oblique pillar in the printing due to its arc characteristics, and the forming effect is better than that of the cubic lattice.